Solving the above problems accurately is usually a highly professional job, involving many specialized instruments, such as gem microscope, refractometer, spectroscope, polarizer, densimeter and so on. , and specialized testers. So, are ordinary customers very helpless? Not necessarily. Different kinds of jade will inevitably lead to different characteristics, and different characteristics will inevitably lead to different sensory effects. As long as we learn to use the sensory effects of these characteristics, even if there is no instrument to measure accurate data or identify their characteristics, we can at least be suspicious and vigilant about fake and shoddy products and protect our own interests. Therefore, the following are mainly some identification methods that do not require instrument detection. If you encounter problems that cannot be solved, you should consider handing them over to testing institutions for solution.
(1) Identification of New Jade Articles
Before distinguishing between true and false, we must first know the real jade species. If you don't even know what the real jade species is, you can't tell the true from the false. Some jade varieties will not admit their mistakes as long as they have seen them once, because they are so special and really different that they are easy to leave a deep impression on people. Such as malachite, lapis lazuli, agate, rhodochrosite, hematite, turquoise, wood and stone, etc. Some jadeites are similar to each other, which is easy to cause confusion, such as nephrite, glazed jade, white and delicate quartzite jade and calcite jade; For example, between jadeite A and jadeite B and C, dyed quartzite and green devitrified glass; Such as crystal and fluorite; Such as beeswax topaz and topaz and so on. The identification of similar jade should not only see more, but also understand its physical properties, structural characteristics and characteristics. Have a theory as a guide, then read more books and accumulate practical experience to identify.
In the last article about jade varieties, we introduced the properties and characteristics of various jade in detail. In fact, among all the dozens of kinds of jade, there are not many kinds of jade with fake products after artificial treatment, so it can be said that there are only a handful. For example, jade varieties with counterfeit products include nephrite, jadeite, olivine, turquoise and crystal. There are nephrite, jadeite, azurite, turquoise, crystal, quartzite jade, serpentine jade, chalcedony, calcite jade and so on. In addition to the above, most jade species rarely have fakes and artificial processed products, because its value and customer recognition determine that it has not yet developed to the point where it needs imitation processing. On the contrary, some may imitate the jade species mentioned above. For these jade species, as long as the jewelry store marks the name, what we have to do is not identification, but appreciation. This is it! We only introduce the identification of some jade species with counterfeit and processed products mentioned above, but we will once again emphasize the typical characteristics of some jade species with typical characteristics to Otsuka for identification.
1. Identification of nephrite and its counterfeits
Nephrite is generally treated artificially, which is relatively rare. Because it is white, there is no need to try dyeing. Nephrite is a precious jade since ancient times. So there are fakes. The most common counterfeit products are serpentine jade, quartzite jade and calcite jade.
The sensory characteristic of nephrite is luster, which is oily luster or glassy luster with oily feeling. In short, there is always a moist and soft feeling in its luster; Second, structure, nephrite is a kind of jade composed of interwoven fibrous small crystals. It can be seen that variegated jade is composed of interwoven fibrous small crystals, but there are no transparent granular small crystals, which are called "speckled crystals"; The third is transparency. Compared with jade that may be confused, its transparency is relatively poor. Although it is translucent to opaque, in fact, most jade is slightly transparent, and translucent nephrite is not easy to see.
Serpentine jade: It is usually distinguished from nephrite by its light yellow-green or light green color and good transparency. However, serpentine jade also has white varieties, and its differences from nephrite are as follows: First, the luster of serpentine jade is weaker than nephrite, and it is usually more waxy; The second is the structure. The structure of serpentine jade is actually similar to nephrite, but serpentine jade does not see the mottled structure of nephrite regularly distributed, but often or almost always sees some white "clouds" distributed in translucent and uniform jade; Third, the sense of balance should be lighter, because the density of serpentine jade is lower than nephrite, and the difference in density is enough to cause the difference in hand balance, which of course requires more practice; The fourth is hardness, which can only be known after being scored with a certain tool. This destructive method is generally not allowed. However, if other methods can't solve the problem, you can consider scratching the bottom or inconspicuous place of the jade with a small steel knife, or scratching the glass with an inconspicuous sharp part of the jade to get the effect. Because the hardness of steel blade is usually 5.5 ~ 6, and the hardness of window glass or glass plate is 5 ~ 5.5, the hardness of high-quality serpentine used as jade is usually around 5, and nephrite is above 6. So steel knives should be able to scratch serpentine jade, but serpentine jade can't scratch glass. Nephrite can be distinguished from ordinary glass because it won't be scratched by a steel knife.
Quartzite jade: It is often used to imitate nephrite, especially white and delicate varieties. Although the colors of green Dongling Stone and Miyu are similar to those of Jasper, the typical scaly green mica inclusions contained in them are easily distinguished from Jasper. The difference between quartzite jade and nephrite is: first, the structure, quartzite jade is a granular structure, when its particle size is coarse, particles can be seen by naked eyes, but when its particle size is fine, there is no "mottling" of nephrite; Second, luster, quartzite jade has a typical glass luster, which is different from nephrite; Third, the density difference, the density of quartzite is lower than nephrite, and it feels lighter. If the three cannot be distinguished, a refractometer and a microscope are needed. Of course, this is the job of professionals.
Calcite jade: It is also often used to imitate white jade, especially the so-called "afghanistan white jade" that appeared in recent years, which is very similar to white jade. Many customers have been cheated, thinking that they have bought a good white jade at a reasonable price. In fact, the so-called "afghanistan white jade" is a kind of white marble with very delicate texture, belonging to calcite jade. As long as we know the method, it is easy to distinguish calcite jade from nephrite. First, look at the structure. Calcite jade or marble jade is a granular structure. When the texture is rough, small granular crystals can be seen. When the texture is fine, you can't see the mottled structure unique to nephrite. Second, the density difference. The density of calcite jade is slightly lower than that of nephrite, so you can feel the difference of hand feeling after more practice, and calcite jade has a lighter hand feeling. Third, hardness, it is best not to use this destructive method, but this method is very effective, because the hardness of calcite jade is generally around 3 ~ 3.5, and it can be brushed down with one knife. Of course, you can't scratch the glass, but you can leave white powder stripes on the unglazed porcelain board, and nephrite is definitely not good; Fourth, acid measurement method, calcite jadeite will react violently when it meets dilute hydrochloric acid, and it will bubble violently when it meets acid solution. If you happen to have dilute hydrochloric acid solution on hand (the main ingredient of some toilet cleaner is dilute hydrochloric acid), you can dip it slightly with a toothpick and aim it at the bottom of the jade or an inconspicuous place to see if there is any bubbling. If it bubbles, it is calcite jade, not nephrite.